Some years elapsed after his victory at Hastings before the power of the conqueror was thoroughly established throughout the northern provinces of England, and even then it is doubtful whether it ever extended, except in a qualified degree, over the modern county of Cumberland, or over Northumbria beyond the Tyne.[152] He was well aware of the secret disaffection existing amongst the magnates of his new people, but it formed no part of his policy to drive them in a body into open rebellion, and they were retained in a species of honourable captivity at his court, or accompanied him in his expeditions into Normandy--nominally indeed as dignified retainers, but in reality as hostages for the peace of their respective districts--whilst year after year saw one or more of the nobles of English birth incarcerated or put to death on one pretext or another. The vengeance of William might be postponed, but it was never forgotten, nor did he ever pass over an opportunity of crushing the man whom his sagacious but unsparing policy had once marked as dangerous. [Sidenote: A. D. 1068.] It was to avoid some such ebullition of William’s wrath, that, in the summer of 1068, Edgar the Atheling, with his mother and two sisters, and many of the northern lords who had supported his claims after the death of Harold, deemed it expedient to cross the borders into Scotland. There appears to have been an abortive attempt at a rising in that year in which the fugitives may have been implicated, and, to curb the disaffection of the men of Morkar’s earldom, William built two castles at York, garrisoning them with a strong detachment of Norman soldiery. [Sidenote: A. D. 1069.] In the ensuing winter he dispatched Robert Comyn, the first of a name destined to become celebrated in the annals of the neighbouring kingdom, to preserve order amongst the turbulent Northumbrians beyond the Tyne; [Sidenote: 28th Jan.] but the Norman baron was surprised and slain at Durham, before he reached his earldom, out of seven hundred of his followers but one escaping with life. The perpetrators of this outrage then marched upon York, taking with them Edgar, who had joined them from Scotland, and were entering into a negotiation with the citizens of that place, when they were discomfited by the sudden arrival of William from the south, who gave up the city to be plundered, as a punishment for the disaffection of its inhabitants.[153] [Sidenote: Sept.]